54 WILD LIFE IN A SOUTHERN COUNTY. 



nights, when it has been sufficiently clear to distin- 

 guish them, I have noticed that the particular down 

 on which the earthwork is situate shows more distinctly 

 than the others. By day no difference is apparent ; 

 but sometimes by night it seems slightly lighter in 

 hue, and stands out more plainly. This may perhaps 

 be due to some unobserved characteristic of the 

 herbage on its slope, or possibly to the chalky sub- 

 soil coming there nearer to the surface. The power 

 of reflecting light possessed by the earth, and varied 

 by different soils or by vegetation, is worth observa- 

 tion. 



